• Register Today It's free! This box and some ads will disappear once registered!

Vent blows hot

Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
no matter what the temperature setting is, the vent blows hot. There is no noticeable change in temperature from 60-90 degrees, and when you turn it to “max ac” you can hear the rpms kick up slightly but the compressor never kicks on. All the vent settings (defrost, floor, etc...) all work.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
Blend door or blend door actuator not working? Both are fairly common problems. Begin by running the EATC self diagnostics (ing key ON, press OFF on the EATC control panel, press OFF and FLOOR at the same time and then within 2 seconds press AUTOMATIC). The test takes around 30 second and when done will display 888 if okay, or various codes (like 024 or 025) if the test finds faults.

The actuator isn't too hard to replace, but unless you do the "quick fix" (cutting the heater box for access) replacing the blend door requires removing the dash. I've had to replace the actuators on 3 off my Explorers/Mountaineers.

The below link might be helpful:
Dorman 604-201 EATC Blend Door Actuator review
 




J_C

Explorer Addict
Joined
July 30, 2009
Messages
3,411
Reaction score
518
City, State
Florence, KY
Year, Model & Trim Level
1998 XLT 4WD 4.0L SOHC
Since the compressor never kicks on, I would suspect a compressor clutch fault or at least the fuse to it (if not both). You could carefully (keeping away from the fan and belt) measure for 12V getting to the clutch connector when the compressor should be running, but it's easier to see if 12V is going through the fuse to it first, then if no 12V through the fuse, no need to check at the clutch as the problem is upstream of it (or again it could be both, that a shorted clutch coil blew the fuse).
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
Since the compressor never kicks on, I would suspect a compressor clutch fault or at least the fuse to it (if not both). You could carefully (keeping away from the fan and belt) measure for 12V getting to the clutch connector when the compressor should be running, but it's easier to see if 12V is going through the fuse to it first, then if no 12V through the fuse, no need to check at the clutch as the problem is upstream of it (or again it could be both, that a shorted clutch coil blew the fuse).

Oh, I read that wrong. I thought he said the compressor did kick on. If it doesn't, that might be due to low a refrigerant level, bad pressure switch, or even a problem with a small relay inside the EATC unit (due to a broken to a broken solder joint) that turns on the compressor. You can rule out the compressor clutch by running 12V power directly from the battery to the clutch's connector. If the clutch engages it's good. You can also jump the pressure switches with a paper clip, though that doesn't rule out low refrigerant.
 




Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
So the blend door actuator is completely missing, I can move the blend door and make it go from hot to cold, but it feels like it’s loose in there like there is no bottom piece to center it.
 




GLOCKer

Well-Known Member
Joined
April 30, 2018
Messages
537
Reaction score
116
Location
ATL Area
City, State
Marietta, GA
Year, Model & Trim Level
1998 Explorer Limited
So the blend door actuator is completely missing, I can move the blend door and make it go from hot to cold, but it feels like it’s loose in there like there is no bottom piece to center it.

Wow that sucks! A little bit of good news: You can easily source a blend door "repair" kit and actuator online (Amazon for instance). The bad news is that the blend door repair requires you take out the whole dash or cut up the box and patch it back together. Some of the blend door repair kits actually come with a template to show you where to make the cuts to get into the box, and also include aluminum tape to help seal the box back up again. As far as the actuator is concerned; it's a pretty easy to replace.

I got lucky! During this past summer, I was getting cold air out of the vents but after a little while it would blow hot (especially on the interstate). Then during this winter I was not getting enough heat to be comfortable. I pulled the HVAC fuse and set to trying to diagnose the blend door actuator. My thoughts were it was probably stuck somewhere in between and causing my issues. I put the fuse back in and ran the temp controls on the automatic unit and I saw the actuator was working. I popped it back on and low-and-behold my heat worked perfectly after that!

These HVAC units are a crap shoot! LOL
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
If the blend door is the issue, there is a "quick fix" you can do to replace it. I'll find it and post a link to it. It involves cutting an access hole in the heater box from the interior, installing a new blend door and then you reseal the heater box afterwards. It far easier than removing the entire dash.

Link:
How to: 2nd Gen Blend Door Quick Fix

I doubt it only takes 5 mins, but maybe you can do it in 30 mins. As you don't have an actuator, you'll also need an "automatic" actuator. Make sure you get the "automatic" version which works with the EATC. The "manual" version looks the same externally, but is a completely different animal. The Dorman 604-201 is the least expensive version of the actuator at under $20 on eBay.

BTW - With or without a working blend door, your A/C compressor should still kick-in and cycle ON/OFF when you push the MAX button on the EATC control panel. If it's not engaging that will be a separate issue.
 




Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
I went ahead and bought an actuator from Napa, and threw it in to see what would happen. Now the vents blow cold at 60 and hot at 90, but when I flipped it back to 60 it blew hot. I did the EATC diagnostics and it just showed 888 and had all the little symbols light up. I turned it off and turned it back on, and the vents blew cold again at 60. It seems like if I set it to 90, the only way to get the vents blowing cold again is to run the EATC test, but have it at 60 beforehand, and restart it. It is about 40 degrees Fahrenheit right now. Will this figure itself out overtime, is there some kind of reset procedure for when you install a new actuator, or is there something wrong? I did get the automatic actuator.
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
I went ahead and bought an actuator from Napa, and threw it in to see what would happen. Now the vents blow cold at 60 and hot at 90, but when I flipped it back to 60 it blew hot. I did the EATC diagnostics and it just showed 888 and had all the little symbols light up. I turned it off and turned it back on, and the vents blew cold again at 60. It seems like if I set it to 90, the only way to get the vents blowing cold again is to run the EATC test, but have it at 60 beforehand, and restart it. It is about 40 degrees Fahrenheit right now. Will this figure itself out overtime, is there some kind of reset procedure for when you install a new actuator, or is there something wrong? I did get the automatic actuator.

Running the diagnostics resets the EATC and actuator. This should not be required to do more than once. Without the actuator installed you should have been able to flip the blend door easily (no real resistance) manually from open to closed within about a 1/4 of a turn. It should not have felt sloppy. If it felt sloppy (like it was not connected to it's pivot points) then my guess is it's broken,
 




CDW6212R

Hauls the mail.
Elite Explorer
Joined
June 17, 2004
Messages
21,219
Reaction score
1,969
City, State
Knoxville, TN
Year, Model & Trim Level
98 Limited AWD
If the compressor wasn't working apparently, be sure it does come on properly.

The compressor should run at all times except when the controls are set to "OFF" or "VENT." Watch the compressor with the engine running and the AC on, it should turn on and off intermittently, based on the freon charge, and pressure in the lines. If it isn't predictable as you watch it for a couple of minutes, than something is wrong with the freon level or the compressor/circuit. If the compressor is fairly noisy, check with the engine off, how loose is the clutch moving forward/backward. At this age it's getting to be time to replace the AC clutch on most Explorers.
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
If the compressor wasn't working apparently, be sure it does come on properly.

The compressor should run at all times except when the controls are set to "OFF" or "VENT." Watch the compressor with the engine running and the AC on, it should turn on and off intermittently, based on the freon charge, and pressure in the lines. If it isn't predictable as you watch it for a couple of minutes, than something is wrong with the freon level or the compressor/circuit. If the compressor is fairly noisy, check with the engine off, how loose is the clutch moving forward/backward. At this age it's getting to be time to replace the AC clutch on most Explorers.

As I understand it, The compressor may run on all settings except OFF and VENT. That's why I suggested testing it on the MAX setting. In any event the OP just said he got cold air after installing the blend door actuator, but only after setting the temp to 60 and resetting the EATC, so apparently the compressor is working. In the battle between HEAT and A/C, HEAT wins.
 




CDW6212R

Hauls the mail.
Elite Explorer
Joined
June 17, 2004
Messages
21,219
Reaction score
1,969
City, State
Knoxville, TN
Year, Model & Trim Level
98 Limited AWD
I know that well, my Mercury still has the blend door issue that I haven't had time to fix. When the blend door is open to the heater core, MAX AC blows nice warm air. I used to slap the dash each time I started it, and once in a dozen times the blend door would be moved to the cold side. But it's hard to not have the controls set to a temperature that doesn't command heat when the EATC is first turned on. Cool mornings make the actuator command heat, so bingo, heat again for many days or weeks during Spring-Fall. When I was driving that a lot, I would try hard to keep it on MAX AC, adjusted to a proper temperature. The MAX AC does stop the actuator from commanding heat.
 




Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
I’ve heard you could replace the blend door by removing the evaporator housing under the hood. I know that I have to recover the refrigerant to do this, but it seems a bit easier than pulling the dash out. Is that true?
 




lobo411

Well-Known Member
Joined
September 14, 2011
Messages
921
Reaction score
53
Year, Model & Trim Level
1996 Explorer 4.0 OHV
I’ve heard you could replace the blend door by removing the evaporator housing under the hood. I know that I have to recover the refrigerant to do this, but it seems a bit easier than pulling the dash out. Is that true?

It's way easier to cut a hole in the air box from inside the car, replace the blend door, glue the piece you cut out back in, and then seal everything with aluminium HVAC tape. Takes about 30 mins, and there's even a sticky about it.
 




Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
The vent blows cold when you run the test, and I could live with it. But the compressor clutch still never engages. Here’s what I know. When you turn it to defrost or max ac you hear the rpms kick up, but it never actually engages. The scanner says the compressor is on in defrost or max ac. I found there is no power getting to the clutch. I swapped relays still with no luck. Now where is the fuse at for the compressor?
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
Check your owner's manual (assuming you have one) regarding fuse locations. Alternately just check all the fuses in the power distribution box and in the cabin's fuse box.

As I told you previously, there is a small relay inside the EATC unit that turns the compressor ON. What has happened to others here is that the relay's solder joints on the EATC's circuit board crack and then the compressor doesn't get the signal to run. There is also a WOT (wide open throttle) relay that is designed to turn OFF the compressor at WOT. Finally there are HIGH and LOW pressure switches that prevent the compressor from running if the refrigerant pressure is to low, or to high. You have to work through it to find the problem.
 




CDW6212R

Hauls the mail.
Elite Explorer
Joined
June 17, 2004
Messages
21,219
Reaction score
1,969
City, State
Knoxville, TN
Year, Model & Trim Level
98 Limited AWD
Go to the low pressure switch and check for power there next. That's the two wire connector on the dryer at the rear of the engine. If there is power there(either wire)(with AC on), then the EATC or control unit is not the problem. If only one has power with the connector on the LPS, then that sensor is stopping the current right there. That power from there goes through the HPS, and then the WOT relay, before reaching the clutch.
 




koda2000

Explorer Addict
Joined
September 2, 2011
Messages
13,847
Reaction score
1,465
Year, Model & Trim Level
x
Go to the low pressure switch and check for power there next. That's the two wire connector on the dryer at the rear of the engine. If there is power there(either wire)(with AC on), then the EATC or control unit is not the problem. If only one has power with the connector on the LPS, then that sensor is stopping the current right there. That power from there goes through the HPS, and then the WOT relay, before reaching the clutch.

Or just jump the LPS switch with a paper clip to see if the compressor kicks in. If it does it doesn't necessarily mean the LPS is bad. Could be you're low on refrigerant.

You can do the same with the HPS, but if compressor kicks in you may have too much refrigerant in the system.
 




Zman302

Member
Joined
January 27, 2019
Messages
23
Reaction score
0
Year, Model & Trim Level
1998 Explorer Eddie Bauer
So I am getting 14 volts at both the high pressure and low pressure switch. I tried jumping each with a paper clip and the compressor still doesn’t kick on. You can hear the idle speed change when you jump them with the clip and plug them back in. I just discovered a relay box right below the air filter box. I can’t find any diagrams of where that wot relay is at. And I don’t have an owners manual for that vehicle.
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private Conversations, and more. Join Today. Your support is greatly appreciated.




CDW6212R

Hauls the mail.
Elite Explorer
Joined
June 17, 2004
Messages
21,219
Reaction score
1,969
City, State
Knoxville, TN
Year, Model & Trim Level
98 Limited AWD
Progress, good, keep going. Now check for voltage at the compressor itself, there should be something there only when the AC is on etc. If that shows voltage, than the WOT relay should be working, letting current through. It's a constant on relay, only shutting off current when the engine is WOT.

If voltage shows at the compressor, than there is a power loss along the path, I'd start at the AC unit if that's the case.
 




Top